Show activity indicator with lazy loading using AsyncImageView classes - iphone

Question

I am using AsyncImageView classes to apply lazy loading on UITableView. And want to apply activity indicator on image view until the image is loaded on cell. Below is my code i am trying.
// AsyncIamgeView.m
- (void)connectionDidFinishLoading:(NSURLConnection*)theConnection {
//[connection release];
UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
indicator.center = CGPointMake(15, 15);
connection=nil;
if ([[self subviews] count]>0) {
[[[self subviews] objectAtIndex:0] removeFromSuperview];
}
UIImage *imgData = [UIImage imageWithData:data];
UIImageView* imageView = [[UIImageView alloc]init];
[imageView addSubview:indicator];
[indicator startAnimating];
if(imgData == nil)
{
imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"NoImagenew.png"]];
//[indicator stopAnimating];
}
else{
imageView = [[UIImageView alloc] initWithImage:imgData];
// [indicator stopAnimating];
}
//imageView.contentMode = UIViewContentModeScaleAspectFit;
//imageView.autoresizingMask = ( UIViewAutoresizingFlexibleWidth || UIViewAutoresizingFlexibleHeight );
//[imageView sizeToFit];
[self addSubview:imageView];
imageView.frame = self.bounds;
//imageView.frame = CGRectMake(0, 0, 85, 94);
[imageView setNeedsLayout];
[self setNeedsLayout];
//[data release];
data=nil;
}
// cellForRowAtIndexPath method.
asyncImageView = [[AsyncImageView alloc]initWithFrame:CGRectMake(1, 3, 85, 54)];
[asyncImageView loadImageFromURL:[NSURL URLWithString:imageUrlString]];
[cell.contentView addSubview:asyncImageView];
This code shows activity indicator but when image is loaded after that not before loading images. Please guide for above.

Answer 1

You have to create AsyncImageView object instead of UIImageView, then it will automatically add indicator to your view
AsyncImageView *imageView = [[AsyncImageView alloc] initWithFrame:CGRectMake(1, 3, 85, 54)];
[cell addSubview:imageView];
//cancel loading previous image for cell
[[AsyncImageLoader sharedLoader] cancelLoadingImagesForTarget:imageView];
//load the image
imageView.imageURL = [imageURLs objectAtIndex:indexPath.row];
Here is an example of this

Answer 2

Currently you are adding activity indicator when your image is downloaded.
Here is the simple idea, hope you can implement this in your code
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// This method is called when your connection receives a response
// add your activity indication here and start animating
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// This method is called when your image is downloaded.
// remove your activity indicator or stop animating here
}

Answer 3

Hope u downloaded AsyncImageView from https://github.com/nicklockwood/AsyncImageView. By default, it has the feature to show activity indicator. You just dont need to add or remove any code by yourself to get this feature works. Just call loadImageWithURL.

Answer 4

I think u are using asynimageview classs, In that by default you will get the loader in the cell itself .

Answer 5

AysncImageView already has a loader.
You won't see it if your background is black since it loads the default activity indicator.
So, just set the activityIndicatorStyle property for your AsyncImageView object based on your background.
In my case, my background was black, so I used the following code :
asyncImgView.activityIndicatorStyle = UIActivityIndicatorViewStyleWhite;